STREPTOCARPUS FORMOSUS

STREPTOCARPUS FORMOSUS
For house and garden.
by Lies} van der Walt, Kirstenbosch
midrib and side
alking
branches form
down
thick ridges. The
the
tips
of the leaves
Camphor Avenue
often
die off
at Kirstenbosch,
when plants are
one cannot but
stressed by low
stop to admire
temperatures.
Streptocarpus
Although the
formosus or Cape
brown ends may
primrose as it is
look unattractive
commonly
this survival
known. Growing
tactic does not
in low clumps,
harm the plants
they flower
as the leaves
profusely
simply form an
throughout the
abscission layer
summer months.
and continue to
Formosus,
grow from their
meaning
base.
beautiful, is a
Streptocarpus
perfect
formosus
description of
Above A clump of Streptocarpus formosus growing in the shade of the old Camphor
flowers from
this species with
Avenue, Kirstenbosch.
late spring to
its trumpets of
Below Streptocarpus formosus in its natural habitat, growing on a tree in the
autumn.
One or
Umtamvuna Gorge, KwaZulu-Natal. Photos: L. van de. Walt.
soft mauve and
two
flowers
are
white flowers.
formed at the tips of the long flowering stems. Each
Streptocarpus belong to the family Gesneriaceae, as
leaf usually has a few flowering stems of different ages,
do African violets (Saintpaulia). More than 100 species
shooting from the base. The large trumpet-shaped
of Streptocarpus are found from central Africa to South
flowers are white with soft mauve markings that run
Africa, in Madagascar and in Asia, yet most species are
along the edge of the petals and into the distinctive,
found in southern Africa. In the wild, Streptocarpus
yellow-floored throat. Each delicate flower lasts a few
formosus is found in subtropical forests around Port St
days even when cut
Johns in the Transkei
for
the vase. The
and in the sandstone
plants seem to be se1£gorges of Umtamvuna
pollinated, but are
and Oribi in KwaZulueasily cross-pollinated,
Natal where the
even
with other species.
summers are very humid
Thousands of fine
and hot and the winters
brown seeds are
only marginally cooler
released within a month
and dry. They grow at
or two after flowering.
the bottom of these
When dry, the long
gorges on rocks in small
fruits have an
pockets of well-drained
interesting way of
soil and on the branches
unfolding
like a spiral,
of large trees.
from which the name
Streptocarpus is fasciStreptocarpus(Greek
nating for each leaf is an
streptos = twisted and
individual plant with its
carpus= fruit) is
own roots and flowering
derived.
stems. Streptocarpus
formosus forms thick
Cultivation
clumps - the long,
At Kirstenbosch
strappy, dark green
Streptocarpus formosus
leaves arranged in a
is one of the most
rosette. The leaves are
reliable and beautiful
almost succulent and are
plants in the collections,
covered in little white
flowering as a pot plant
hairs. Their veins are
in the glasshouse and
prominent, especially on
doing well out in the
the underside where the
W
116
cuttings in a warm, humid environrooted, they can be separated and
garden. In a mild climate like Cape
ment out of direct sunlight and
potted into small pots and grown
Town's, the plants survive the
ideally (but not essential) with a
on. This vegetative propagation
winters outside as long as they do
bottom heat of 20-25 DC. A plastic
method will produce young plants
not get too wet. During the warm
bag can be placed over the tray to
identical to their parents. Be careful
summers they are actively growing
and need plenty of water, but
keep the humidity high. Air the
to avoid fungal attacks by using
during the cool winters very little
clean materials and do not keep the
cuttings regularly for a few minutes
and water the soil when dry.
cuttings too cold and wet. If the
water should be given (only when
the plants are dry). Even when
leaves rot before they root,
slightly wilted from drought,
just try again.
they will quickly recover with
a good watering.
Propagation from seed
When planting
Sow Streptocarpus formosus
Streptocarpus in the garden,
seed during the warm spring
prepare the soil well,
and summer months by
scattering the seeds on a
especially under trees, by
moist, well-drained medium
digging proper planting
like fine compost or palm
pockets and adding lots of
matured compost and mulch.
fibre. Place in a position with
Streptocarpus needs good light
good light but not direct
but not direct sunlight: they
sunlight and water regularly
are easily burned by sun yet
with a fine spray - not
reluctant to flower in deep
allowing the seedlings to dry
shade. Light shade with good
out. Germination is usually
within a month. Plant the
ventilation and temperatures
around 17-25 °C are best. They
seedlings out into small pots
in a well-drained medium
respond well to feeding during
summer when they are
when they are quite big and
strong. Transplant again into
actively growing. Remove the
dead leaves and flowers
bigger pots when the roots
regularly, as this keeps the
have filled the small pots.~
plant attractive and healthy.
Further reading
Streptocarpus formosus seem
Dibley, Rex and Gareth. 1995.
to be more resistant to most of
Streptocarpus, A Wisley
the pests like mealy bug, slugs, The long, twisted seed pods that are typical of
Handbook. Cassell. London.
Streptocarpus and from which the name (streptos =
white fly and fungal diseases
Hilliard. a.M. and Burt. B.L. 1971.
twisted and carpus = fruit) is derived. Photo: L. van de. Wall.
Streptocarpus: An African plant
that are often found in other
study. University of Natal Press.
species of Streptocarpus.
Durban
Within a month or two the leaves
Propagation from leaf cuttings
will root and new little leaves will
Acknowledgements
Streptocarpus formosus can easily
start to form along the cut edge that
Thanks to Trevor Edwards who always
help with the identifications, Martin
was placed in the rooting medium.
be propagated from a single leaf.
Kunhardt who has generously given many
This can be done at any time of the
The old leaves turn brown as the
Streptocarpus species to Kirstenbosch and
year except midwinter. Simply
young leaves start to grow. Once the
Dirk Bellstedt for his support with the
break off a healthy, mature leaf.
new plants are strong and well
collection.
There are two methods of
cutting the leaf. Place one
flat on a clean, hard
surface and cut it with a
blade at right angles to the
midrib into segments of
about 4 cm. Alternatively,
cut along the length of the
leaf blade and remove the
large central vein. Then
prepare a tray with a welldrained soil medium like
sand or compost and
wedge the cut edges
firmly into it. Water
thoroughly and place the
Right Leaf cuttings of
Streptocarpus cut in segments
and placed in sand.
Far right Leaf cuttings cut
along the length of the leaf
blade. Photos: NBI.